Fixed #336

Marlin/thermistortables.h

 
 //Set the high and low raw values for the heater, this indicates which raw value is a high or low temperature
 #ifndef HEATER_0_RAW_HI_TEMP
-# if HEATER_0_USES_THERMISTOR   //In case of a thermistor the highest temperature results in the lowest ADC value
+# ifdef HEATER_0_USES_THERMISTOR   //In case of a thermistor the highest temperature results in the lowest ADC value
 #  define HEATER_0_RAW_HI_TEMP 0
 #  define HEATER_0_RAW_LO_TEMP 16383
 # else                          //In case of an thermocouple the highest temperature results in the highest ADC value
 
 //Set the high and low raw values for the heater, this indicates which raw value is a high or low temperature
 #ifndef HEATER_1_RAW_HI_TEMP
-# if HEATER_1_USES_THERMISTOR   //In case of a thermistor the highest temperature results in the lowest ADC value
+# ifdef HEATER_1_USES_THERMISTOR   //In case of a thermistor the highest temperature results in the lowest ADC value
 #  define HEATER_1_RAW_HI_TEMP 0
 #  define HEATER_1_RAW_LO_TEMP 16383
 # else                          //In case of an thermocouple the highest temperature results in the highest ADC value
 
 //Set the high and low raw values for the heater, this indicates which raw value is a high or low temperature
 #ifndef HEATER_2_RAW_HI_TEMP
-# if HEATER_2_USES_THERMISTOR   //In case of a thermistor the highest temperature results in the lowest ADC value
+# ifdef HEATER_2_USES_THERMISTOR   //In case of a thermistor the highest temperature results in the lowest ADC value
 #  define HEATER_2_RAW_HI_TEMP 0
 #  define HEATER_2_RAW_LO_TEMP 16383
 # else                          //In case of an thermocouple the highest temperature results in the highest ADC value
 
 //Set the high and low raw values for the heater, this indicates which raw value is a high or low temperature
 #ifndef HEATER_BED_RAW_HI_TEMP
-# if BED_USES_THERMISTOR   //In case of a thermistor the highest temperature results in the lowest ADC value
+# ifdef BED_USES_THERMISTOR   //In case of a thermistor the highest temperature results in the lowest ADC value
 #  define HEATER_BED_RAW_HI_TEMP 0
 #  define HEATER_BED_RAW_LO_TEMP 16383
 # else                          //In case of an thermocouple the highest temperature results in the highest ADC value